Hedge trimmer



Nov. 13, 1934. R. 'r. KAUFFMAN HEDGE TRIMMER Filed Sept. 11, 1933 2Sheets-Sheet l R. T. KAUFFMAN HEDGE TRIMMER Filed Sept. 11, 1933 2Sheets-Sheet 2 Patented Nov. 13, 1934 UNITED STATES PATENT OFFICE 1Claim.

This invention has for its object the provision of a hedge trimmer ofsimple and compact form which may be easily handled and in which thecutter will be driven by a motor mounted upon the frame so that themanual effort required will be minimized. The stated object and otherobjects which will appear incidentally during the course of thefollowing description are attained in such a device as is illustrated inthe accompanying drawings, and the invention resides in certain novelfeatures which will be particularly defined in the appended claim.

In the drawings, Figure 1 is a side elevation of a hedge trimmerembodying the present invention.

Figure 2 is a longitudinal section with the motor in elevation,

Figure 3 is a plan view with the cover removed. In carrying out thepresent invention, there 2() is provided a frame or housing consistingof a lower member 1 and a cover 2, the lower member having a flat baseso that it may rest horizontally upon the top of a hedge or be heldperpendicularly against the side of the hedge, and being 5 furtherprovided with an opening 3 which re ceives the lower portion of anelectric motor 4 which may be of any known form and is illustrated in aconventional manner. The cover 2 is secured removably upon the basemember 1 and abuts the forward end of the motor, while a supplementalcover 5 is provided and secured upon a semi-cylindrical extension 6, atthe rear end of the base, the cover 5 being also semi-cylindrical sothat when it is in place upon the extension 6 a tubular handle will beproduced through which an electric cable '7 may be carried to supplycurrent to the motor. The cable 7 may be of any desired length butshould be quite long so that the plug 8 at the free end of the cable maybe engaged in a socket in a convenient location upon an adjacentbuilding. It may be further noted that the screw 9 which holds the cover5 upon the tubular extension 6 may be passed between the strands of thecable '7 so that the cable may be prevented from pulling out from themotor. It may also be noted that a passage 10 is preferably provided inthe base member 1 at the forward end of the handle extension throughwhich the cable passes to reach and be properly secured to the motor.

The base member 1 of the frame or casing is provided with a circularchamber 11 in its upper side and from the walls of this chamberdivergent arms 12 extend forwardly, the forward ends of saidarms beingrabbeted and having a stationary knife 13 secured in the rabbets, asclearly shown in Figure v2. Intermediate lesser arms 14 also divergeforwardly from the front wall of the chamber 11 and these arms areconnected by a web 15 on their undersides, said web projecting under thestationary knife 13 at the center of the same. The arms 12 are alsoconstructed at their extremities with overhanging heads 16 which aredisposed above the movable cutter 17 which rests upon the stationarycutter. The 5 movable cutter is constructed adjacent its ends with slots18 running parallel to its rear edge, and through said slots bolts orrivets 19 pass to keep the cutter in a rectilinear path while it isoperating and also to limit its movements. The bolts or rivets 19 areengaged in the heads 16 and the rabbeted terminals 20 of the severalarms so that the movable cutter will be held in place and maintained inproper operative position. At its center, the movable cutter is formedwith a socket 21 in its rear edge and a keeper block 22 is secured uponthe cutter over said socket, said keeper being recessed in itsunderside, as shown at 23, to accommodate the front end of a lever orrocking arm 24 whereby motion is imparted to 0. the cutter. The lever 24is fulcrumed upon a pin 25 which is engaged in sockets provided thereforin the upper side of the base 1 and underside of the cover 2, as clearlyshown in Figure 2, and the rear end of the lever is constructed with a 5longitudinal slot 26 which is engaged by a wrist pin 27 on the upperside of a driving gear wheel 28 which is disposed within the chamber 11of the base. The gear wheel 28 meshes with a pinion 29 carried by avertically disposed shaft 30 having its lower end journaled in the baseat the rear of the chamber 11 and its upper end journaled in a boss 31provided on the underside of the cover 2, it being noted that the gear28 is provided centrally with a trunnion 32 which seats in a socketprovided therefor in the base. The shaft 30 carries a beveled gear 33which is housed within the cover, as clearly shown in Figure 2, andmeshes with a beveled pinion 34 on the front end of the motor shaft 35.

The construction and arrangement of the several parts of the apparatushaving been thus made known, it is thought the operation and advantagesof the device will be readily understood and appreciated. The device isplaced in position upon 5 the top or at the side of the hedge and theplug 8 is engaged in a socket so that current will be supplied from thehouse electric system, and it may be noted at this point that ifdesired, a switch may be inserted in the cable at the motor so that theoperator may control the current without being under the necessity ofreturning to the house and withdrawing the plug. Such a switch has notbeen illustrated in the drawings inasmuch as it forms no part of myinvention and may be of any well known form. The machine having beenplaced in position and the current supplied to the motor, the motorshaft will be caused to rotate and the rotation of the shaft will betransmitted through the pinion 34 and gear 32 to the shaft 30 which inturn will transmit the motion to the gear wheel 28 through the pinion29. The wrist pin 27 is, of course, eccentric-to the gear wheel and asthe gear wheel rotates the wrist pin will, consequently, move along theslot 26 and cause oscillation of the lever 24, the oscillation of thelever through the engagement of its front end with the socket on themovable cutter being translated into reciprocation of the cutter so thatthe projecting stems of the hedge will be quickly and easily severed asthe machine is pushed along the hedge. It may be noted that the strokeof the cutter will be comparatively short but will be very rapid so thatthe desired cutting operation will be quickly and easily performed, thetwigs and stems being guided and held by the lower stationary knives andquickly severed as the reciprocating knives strike against them. While Ihave shown and described the covers 2 and 5 as separate elements, itwill be understood that they may be formed integral and suitablyshapedto fit around or over the motor and the cover will extend over theoperating mechanism which will be housed between the same and the basemember of the frame so that it will be thoroughly protected and thesevered ends of twigs and stems cannot find their way into the operatingmechanism to clog the action of the same and possibly break some of theengaging parts. The cover and base member together form a housing whichmay be filled with lubricant so that the moving parts will be thoroughlylubricated and will operate easily at all times, the grease workingforward from the driving gears along the lever to the cutter. The deviceis very compact and may be very easily manipulated. The cutter is drivenentirely by the power of the electric motor so thatthe only laborrequired of the operator is to guide themachine and hold it in properposition against the hedge.

Having thus described the invention, I claim:

A-hedge trimmer comprising a frame having forwardly diverging arms andprovided in its upper side between the rear ends of said arms with achamber, there being an opening at the rear of said chamber extendingthrough the entire height of the frame, a cover over said chamberextending to the front end of the frame and provided in its undersidewith a chamber registering with the with a longitudinal slot, a gearWheel in the chamher in the frame under the rear end of the lever, an

eccentric wrist pin on said gear wheel engaging the longitudinal slot inthe lever, an electric motor mounted upon the frame with its shaftextending longitudinally of the frame and journaled between the coverand the frame, the front end of the motor abutting the cover and itslower portion projecting into the opening extending through the frame, avertical shaft having its ends journaled in the cover and the framerespectively, gearing connecting said vertical shaft with the motorshaft, and a pinion upon said vertical shaft meshing with the gear inthe chamber in the frame.

ROBERT T. KAUFFMAN. [L. s.]

